The present invention relates to a tilting and telescopic steering column assembly for a vehicle.
A tilting and telescopic steering column assembly includes a tilt mechanism for appropriately adjusting an angle of inclination of a steering wheel (i.e., a vertical position of the steering wheel), a telescoping mechanism for appropriately adjusting an axial position of the steering wheel (i.e., a fore-and-aft position of the steering wheel), and a lock mechanism or lock mechanisms for rendering the tilt and telescoping mechanisms inoperative and thereby locking the steering wheel at an adjusted position.
At present, there are some types of tilting and telescopic steering column assemblies.
One type of tilting and telescopic steering column assembly includes a column jacket provided with upper and lower jacket tubes for supporting therein a steering shaft. The upper jacket tube is slidably inserted in the lower jacket tube so that the column jacket can telescope together with the steering shaft. In such a tilting and telescopic steering column assembly, two separate lock mechanisms are provided: one is exclusive to a tilt mechanism and the other is exclusive to a telescoping mechanism. The steering column assembly thus requires a large number of parts, which results in a significant increase in the weight and manufacturing cost of the steering column assembly.
Another type of tilting and telescopic steering column assembly has a single lock mechanism that combines the above two lock mechanisms, i.e., capable of rendering both of tilt and telescoping mechanisms inoperative using a single operation lever. However, this type of steering column assembly cannot always attain sufficient support rigidity of the telescopic section of a column jacket due to structural restrictions. In addition, the lock mechanism has a complicated structure.
It is therefore an object of the present invention to provide a tilting and telescopic steering column assembly provided with a telescopic column jacket, which can make its tilt and telescoping mechanisms locked or unlocked simultaneously in a single operation step and presents the following features (1) to (3).
(1) The steering column assembly has a simple structure built up of a smaller number of parts, whereby its manufacturing cost can be reduced.
(2) The steering column assembly can attain improved strength of locking a steering wheel at an adjusted position.
(3) The steering column assembly can attain sufficient support and dynamic rigidity, especially of the telescopic column jacket.
According to one aspect of the present invention, there is provided a steering column assembly for a vehicle, comprising: a column jacket having upper and lower jacket tubes telescopically coupled with each other; a steering shaft rotatably supported in the column jacket and capable of tilting and telescoping together with the column jacket; upper and lower clamps mounting the column jacket on a vehicle body in such a manner that the column jacket can tilt about a lower end portion of the lower jacket tube, the upper clamp having a pair of opposed sidewalls and first and second distance brackets disposed movably between the sidewalls so as to sandwich the column jacket therebetween, the first distance bracket including a lock portion engageable with an outer surface of the upper jacket tube, the second distance bracket including a support portion engageable with an outer surface of the lower jacket tube; and an operation lever attached to the upper clamp so as to be able to pivot between a lock position and an unlock position, wherein, when the operation lever is at the lock position, the sidewalls is caused to press the first and second distance brackets against the column jacket with the lock portion pushed on the upper jacket tube and the support portion pushed on the lower jacket tube so that both of the column jacket and the steering shaft are prevented from tilting and telescoping.
According to another aspect of the present invention, there is provided a steering column assembly for a vehicle, comprising: a column jacket having upper and lower jacket tubes telescopically coupled with each other and supporting therein a steering shaft rotatably; a clamp mounting the column jacket tiltably on a vehicle body, the clamp having a pair of opposed sidewalls and first and second distance brackets disposed movably between the sidewalls so as to sandwich the column jacket therebetween, the first distance bracket having a lock portion engageable with an outer surface of the upper jacket tube, the second distance bracket having a support portion engageable an outer surface of the lower jacket tube; and control means for pushing the sidewalls thereby pressing the first and second distance brackets against the column jacket with the lock portion pushed on the upper jacket tube and the support portion pushed on the lower jacket tube so that the column jacket is prevented from tilting and telescoping when an operation lever is in a lock position.
According to still another aspect of the present invention, there is provided a clamp for mounting a column jacket tiltably on a vehicle body, the column jacket having upper and lower jacket tubes telescopically coupled with each other, the clamp comprising: a pair of opposed sidewalls; first and second distance brackets disposed movably between the sidewalls so as to sandwich the column jacket therebetween, the first distance bracket including a lock portion engageable with an outer surface of the upper jacket tube, the second distance bracket including a support portion engageable with an outer surface of the lower jacket tube; and control means for pushing the sidewalls thereby pressing the first and second distance brackets against the column jacket with the lock portion pushed on the upper jacket tube and the support portion pushed on the lower jacket tube so that the column jacket is prevented from tilting and telescoping when an operation lever is in a lock position.